BOTTOM LINE: Attentive service and delicious food, but I'm not sure I experienced the same "WOW" or "MEH" factor that others have.
Listen, this place is good, and I wouldn't hesitate recommending it to others, but it's also not amazing or paradigm-shifting by any means. Judging by the the "bimodal" distribution of Yelp ratings, however, it seems like you're either a fanboy or a hater.
To the FANBOYS: The service and food were good, but not amaze-balls. My favourite was their unique take on the classic french onion soup - excellent presentation, loved the duck , though would've preferred a bit more cheese. Their heirloom tomato salad could've, again, had more than just a thin slice of barrata. Cod was done well and the deer was cooked to medium-rare perfection (though I prefer a gamier taste, that's just me). And as for the apple confit, the highlight was actually the goat cheese ice cream that accompanied it.
To the HATERS: To those expecting Lucien to be a molecular gastronomic affair comparable to El Bulli, I say, "WTF?! Seriously?" This place is far from it, but last I checked, they weren't advertising themselves as such. A lot of detractors also complain about the price/serving size ratio. On the one hand, I tend to agree if only because I've eaten at other comparably good restaurants for less but it's not like Lucien's prices are outrageously expensive (although I wasn't exactly rushing to order their chef's tasting menu!). On the other hand, given how everything else in the neighbourhood is in the same price range and there's this thing called the Internets, I'm not sure how the cost was beyond people's expectations.
All in all, I like Lucien and that's why it deserves 3 stars. Apparently, I'm only the second or third out of 30 people to think so.